#include <mono/common/directory_iterator_strategy.h>
#include <cassert>

namespace mono {

TraverseBase::TraverseBase(DepthFunPtr depthDeterminer, uint16_t maxDepth)
	: _depthDeterminer(depthDeterminer), _maxDepth(maxDepth)
{
}


inline bool TraverseBase::isFiniteDepth()
{
	return _maxDepth != D_INFINITE;
}


bool TraverseBase::isDirectory(File& file)
{
	return file.isDirectory();
}


//
// ChildrenFirstTraverse
//
ChildrenFirstTraverse::ChildrenFirstTraverse(DepthFunPtr depthDeterminer, uint16_t maxDepth)
	: TraverseBase(depthDeterminer, maxDepth)
{
}


const std::string ChildrenFirstTraverse::next(Stack* itStack, bool* isFinished)
{
	// pointer mustn't point to NULL and iteration mustn't be finished
	assert(!(*isFinished));

	std::stack<DirectoryIterator> it;

	//_depthDeterminer(it);

	// go deeper into not empty directory
	// (if depth limit allows)
	bool isDepthLimitReached = isFiniteDepth() && _depthDeterminer(*itStack) >= _maxDepth;
	if (!isDepthLimitReached && isDirectory(*itStack->top()))
	{
		// check the dir is iterable
		DirectoryIterator child_it(itStack->top().path());
			// check if directory is empty
		if (child_it != _itEnd) {
				itStack->push(child_it);
				return child_it->path();
		}

	}

	++(itStack->top());

	assert(!itStack->empty());
	// return up until there isn't right sibling
	while (itStack->top() == _itEnd) {
		itStack->pop();

		// detect end of traversal
		if (itStack->empty()) {
			*isFinished = true;
			return _itEnd->path();
		} else {
			++(itStack->top());
		}
	}

	return itStack->top()->path();
}


//
// SiblingsFirstTraverse
//
SiblingsFirstTraverse::SiblingsFirstTraverse(DepthFunPtr depthDeterminer, uint16_t maxDepth)
	: TraverseBase(depthDeterminer, maxDepth)
{
	_dirsStack.push(std::queue<std::string>());
}


const std::string SiblingsFirstTraverse::next(Stack* itStack, bool* isFinished)
{
	// pointer mustn't point to NULL and iteration mustn't be finished
	assert(!(*isFinished));

	// add dirs to queue (if depth limit allows)
	bool isDepthLimitReached = isFiniteDepth() && _depthDeterminer(*itStack) >= _maxDepth;
	if (!isDepthLimitReached && isDirectory(*itStack->top()))
	{
		const std::string& p = itStack->top()->path();
		_dirsStack.top().push(p);
	}

	++(itStack->top());

	assert(!itStack->empty());
	// return up until there isn't right sibling
	while (itStack->top() == _itEnd) {
		// try to find first not empty directory and go deeper
		while (!_dirsStack.top().empty()) {
			std::string dir = _dirsStack.top().front();
			_dirsStack.top().pop();
			DirectoryIterator child_it;
			
			// check the dir is iterable
	
			child_it = dir;

			// check if directory is empty
			if (child_it != _itEnd) {
				itStack->push(child_it);
				_dirsStack.push(std::queue<std::string>());
				return child_it->path();
			}
		}

		// if fail go upper
		itStack->pop();
		_dirsStack.pop();

		// detect end of traversal
		if (itStack->empty()) {
			*isFinished = true;
			return _itEnd->path();
		}
	}

	return itStack->top()->path();
}


}
